This invention relates to the field of packaging and, more particularly, to packaging systems incorporating means for protecting the edges and corners of packaged articles, for example, appliances, such as washers, dryers, refrigerators, and the like, and palletized loads of cartons, crates, packages, boxes, bags and like against damage during handling, shipping, and storage. More specifically, this invention contemplates a corner post and tray packaging system having improved strength for packaging and palletizing a wide variety of goods.
In industry today, it is common practice to load diverse products contained in cartons, crates, boxes, bags, and like packages on a pallet and to secure them together by such means as stretch wrap or shrink wrap plastic film or metal or plastic binding straps to secure the packages to the pallet making them easier to move, handle, store, and ship in bulk loads. Consolidation of a multiple of small packages minimizes piece-by-piece handling at terminals, transfer points, warehouses, and the like. Larger articles of manufacture such as appliances are typically also secured to a pallet or slip sheet or are packaged with a special cap to permit movement by trucks. It is further a common practice in industry to employ corner posts at the corner and edges of the packaged load to protect the edges and corners of the packaged article from damage due to contact with other objects or due to impact during moving, handling, or storing. Further, the loads are frequently vertically stacked during shipment or storage to more efficiently utilize space. This stacking which may be three loads high imposes considerable weight on the bottom packages which without the presence of corner posts supporting the weight would tend to crush or collapse the bottom packages. However, the use of corner posts having relatively good compression or stacking strength permits stacking of the loads without crushing those at the bottom of the vertical stack. Thus, a wide variety of appliances such as refrigerators, freezers, air conditioners, and the like are shipped using corner posts to prevent damage to the appliance and to permit stacking of the appliances in a vertical stack to more fully utilize shipping and storage space.
It is also common practice in industry today to wrap a pallet load, article, or package with a plastic film, for example, a stretch wrap film which is tensioned and wrapped around the load, article, or package in the stretched condition after which when the tension is released the film relaxes and shrinks securing the pallet load together. Plastic or metal binding straps may also be used in addition to stretch wrap film to secure a top cap or bottom tray or to secure the load to a pallet, slip sheet or runners to permit lifting of the load with a lift truck. Palletized loads and packaged articles, including top caps, bottom trays, corner posts, and edge protectors enveloped in stretch wrap film are known to the industry.
Corner posts provide the packages with a number of benefits including the following. Strapping and stretch films can be applied tighter without fear of strap indentation or film crushing carton corners. Edges and corners are protected against hard knocks and strap and wrap indentation. Stacking strength is improved to better utilize storage space or space in trailers, rail cars, and containers. Less stretch wrap or fewer straps are required lowering cost. Package alignment and stacking is improved or made easier. Flow of strapping and film around corners is improved.
A wide variety of corner posts and edge protectors are known to the art. For example, Alley U.S. Pat. No. 4,212,394 shows a die cut and scored blank fabricated from corrugated paperboard or other type of stock material which can be erected to cushion edges and corners of a package. My U.S. Pat. Nos. 4,771,893 and 4,865,201 show other corner post constructions.